The present invention relates to a method of forming a computer casing.
Rubber molded over plastic has been known for some time. Recently, translucent plastic pieces having translucent rubber overmoldings have been introduced. The combination of translucent plastic and translucent rubber revealed a previously unrecognized problem. The rubber and plastic do not form a stable interface. The rubber appears to attack the plastic, resulting in cracks and opaque patches appearing in the plastic underneath the rubber overmolding. Such cracks affect the structural integrity of the plastic piece, and the opaque patches are aesthetically unpleasing.
The present invention provides a method of forming a rubber-overmolded casing that involves applying a protective barrier to at least a part of a plastic piece that is part of the casing and then molding a rubber layer onto at least the part of the plastic piece over the protective barrier. In one embodiment, a polyurethane coating provides a protective barrier between a polycarbonate plastic piece and a rubber layer that prevents the rubber layer from attacking the underlying polycarbonate plastic piece.